Cloned lines of C3H mouse prostate epithelial cells have been obtained. These will be characterized by studies of androgen and estrogen receptors and ultrastructually by electron microscopy. The clones exhibiting the greatest prostatic and epithelial characteristics will be treated in culture with various chemical carcinogens. They will be maintained in the original dishes or passaged serially, and will be examined for transformation by criteria of piling-up, growth in soft agar, and induction of plasminogen activators. Transformed cells will be inoculated into C3H mice and the tumors obtained will be diagnosed histologically. If we are successful, adenocarcinomas retaining some prostatic markers will be obtained. The methods developed in the mouse cells will then be applied to human prostate tissues, obtained from autopsy or surgery. We will attempt to transform with chemicals cells derived from normal or hypertrophic prostates to cells that will produce tumors in "nude" athymic mice. Hopefully chemical carcinogenesis in vitro of human prostatic epithelial cells will be accomplished and mechanisms studied.